Priority 26 from the Degenerative Cervical Myelopathy PSP

UNCERTAINTY: What is the incidence of adjacent segment degeneration following surgery for the treatment of DCM? Are there strategies that can be implemented to reduce the incidence of adjacent segment degeneration? (JLA PSP Priority 26)
Overall ranking 26
JLA question ID 0097/26
Explanatory note Fusion of the cervical spine can result in degeneration of adjacent levels and the development of new symptoms. In a systematic review by Lawrence et al (2012), low level evidence concluded that the prevalence of clinical adjacent segment degeneration (ASD) ranges from 11% to 12% at 5 years, 16% to 38% at 10 years and 33% at 17 years. Important predictors of ASD included age greater than 60 years, fusion of  ≤3 levels,  fusing adjacent to the C5-6 and/or C6-C7 levels, a pre-existing disc herniation, and dura mater indentation. The level of evidence for these findings was moderate to insufficient, emphasizing the need for further research. Furthermore, the indications for motion-sparing surgical procedures have not be thoroughly outlined. 
Evidence

Systematic reviews on this topic have explored rates and risk of adjacent segment degeneration following cervical arthroplasty and anterior discectomy and fusion. No guidelines were identified.
Shriver MF, Lubelski D, Sharma AM, Steinmetz MP, Benzel EC, Mroz TE. Adjacent segment degeneration and disease following cervical arthroplasty: a systematic review and meta-analysis. Spine J. 2016 Feb;16(2):168-81.
Luo J, Gong M, Huang S, Yu T, Zou X. Incidence of adjacent segment degeneration in cervical disc arthroplasty versus anterior cervical decompression and fusion meta-analysis of prospective studies. Arch Orthop Trauma Surg. 2015 Feb;135(2):155-160.
Lawrence BD, Hilibrand AS, Brodt ED, Dettori JR, Brodke DS. Predicting the risk of adjacent segment pathology in the cervical spine: a systematic review. Spine (Phila Pa 1976). 2012 Oct 15;37(22 Suppl):S52-64.
Harrod CC, Hilibrand AS, Fischer DJ, Skelly AC. Adjacent segment pathology following cervical motion-sparing procedures or devices compared with fusion surgery: a systematic review. Spine (Phila Pa 1976). 2012 Oct 15;37(22 Suppl):S96-S112.
Health Research Classification System category Neurological 
Extra information provided by this PSP
Original uncertainty examples

What is the incidence of repeat surgery because of ASD?~ Are patients treated for DCM at higher risk for recurrence of myelopathy secondary to adjacent segment degeneration with stenosis?
Submitted by Spinal Surgeons x 8, Other healthcare professionals x 3, People with DCM and their supporters x 0
PSP information
PSP unique ID 0097
PSP name Degenerative Cervical Myelopathy
Total number of uncertainties identified by this PSP. 76  (To see a full list of all uncertainties identified, please see the detailed spreadsheet held on the JLA website)
Date of priority setting workshop 20 November 2019